Horniella confragosa Yin and Li

Yin, Zi-Wei & Li, Li-Zhen, 2014, Revision of the Oriental genus Horniella Raffray (Coleoptera, Staphylinidae, Pselaphinae), Zootaxa 3850 (1), pp. 1-83 : 14-17

2. Horniella confragosa Yin and Li , new species

Figs 3 B, 5–6; Map 1

Type material (2 ♂♂). Holotype, ♂, labeled ‘ CHINA: Guangxi Prov., Xing’an County, Maoershan Mountain , 11.vii.2011, 2,000 m, W.J. He & L. Tang leg. [25°52’12’’N, 110°24’56’’E, leaf litter, sifted] / HOLOTYPE [red], ♂, Horniella confragosa sp. n., det. Yin & Li, 2014, SNUC’ . Paratype, 1 ♂, labeled ‘ China: E. Guizhou, Leishan County, Leigong Shan N. R., nr. Queniao Tea Plantation , 26°24’29’’N, 108°13’42’’E, leaf litter, sifted, ca. 645 m, 4.v.2013, Shu-Lin Yang leg. / PARATYPE [yellow], ♂, Horniella confragosa sp. n., det. Yin & Li, 2014, SNUC’.

Description. Male ( Fig. 3 B). Length 3.69–3.86 mm. Head about as long as wide, HL 0.74–0.79 mm, HW 0.78–0.79 mm; anterolateral genal projections ( Figs 5 C, 6C) distinct, anterior margins nearly rounded; median sulcus between antennal tubercles broad, short, and shallow; scapes ( Figs 5 B, 6B) distinctly expanded at basolateral margins; clubs ( Figs 5 A, 6A) loosely formed by apical three moderately enlarged antennomeres; venter with pair of thick lateral spines ( Figs 5 D, 6D). Maxillary palpomeres II stout, broadened at middle. Each eye composed of about 36 facets. Pronotum slightly longer than wide, PL 0.76–0.79 mm, PW 0.71–0.74 mm. Elytra wider than long, EL 1.00– 1.02 mm, EW 1.42–1.44 mm; discal striae reaching about apical 2/3 of elytral length. Protrochanters and profemora ( Figs 5 E, 6E) each with one distinct ventral spine, protibiae ( Figs 5 F, 6F) simple; mesotrochanters ( Figs 5 G, 6G) each with one ventral spine, mesofemora simple, mesotibiae ( Figs 5 H, 6H) each with preapical row of small denticles on mesal margin; tarsomeres II normal, not extending to beneath tarsomeres III. Abdomen large, AL 1.19–1.26 mm, AW 1.43–1.44 mm, tergite IV (first visible tergite) with median and discal carinae short (Population from Maoer Shan) to absent (Population from Leigong Shan), tergite V lacking median carina. Sternite IX ( Figs 5 I, 6I) nearly oval, with well-sclerotized apical half and membranous basal half. AeL 0.77–0.79 mm; aedeagus ( Figs 5 J–L, 6 J–L) with greatly asymmetric median lobe, right half of median lobe greatly protruding apicad, apex pointed in dorso-ventral view; endophallus composed of two elongate sclerites that partially overlap.

Female. Unknown.

Differential diagnosis. This species is placed as a member of the H. centralis group. The males are externally similar to H. sichuanica and H. tianmuensis by sharing the nearly rounded apical margin of anterolateral genal projections, the distinctly expanded basolateral margins of the scapes, and similar placement of spines on the fore and mid legs. Horniella confragosa can be separated from H. sichuanica by the position of apical projection of aedeagal median lobe, which is on the right half, while H. sichuanica has the left half of aedeagal median lobe protruding apicad; H. confragosa can be separated from H. tianmuensis only by the more distinctly pointed apex of the aedeagal median lobe, and the much shorter sclerites of the endophallus.

Comments. Males of the populations from Mao’er Shan and Leigong Shan have a few slight differences, but are otherwise indistinguishable morphologically. The distance between their localities measures about 225 km, with no obvious geographical barriers between them. The difference in the presence/absence of discal carinae on tergite IV, and in lengths of the sclerites of the aedeagal endophallus are more likely attributed to intraspecific variation rather than species characteristics. Since only a single male is currently available for each locality, we choose a conservative approach here, and provisionally place these populations under the same species, pending access to more material from around or between the two localities.

Distribution. South China: Guangxi; Southwest China: Guizhou ( Map 1 ).

Collection notes. Adults were collected by sifting leaf litter in mixed forests.

Etymology. The specific name ‘ confragosa ’ means ‘difficult, hard’, referring to the difficulty in determining the relationship between the populations from Mao’er Shan and Leigong Shan.

Figures

MAP 1. Distribution of Horniella species in China.

FIGURE 3. Male habitus of Horniella species. A. H. centralis sp. n. B. H. confragosa sp. n. Scales: 1.0 mm.

FIGURE 5. Male diagnostic features of Horniella confragosa sp. n. (Population from Maoer Shan). A. Antenna. B. Scape. C. Right half of head, in dorsal view. D. Head, in lateral view. E. Protrochanter and profemur. F. Protibia. G. Mesotrochanter and mesofemur. H. Mesotibia. I. Sternite IX. J. Aedeagus, in dorsal view. K. Same, in lateral view. L. Same, in ventral view. Scales: 0.3 mm, except B, I = 0.1 mm.